JP5297010B2 - Coloring composition for pixel formation, method for producing color filter, and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colored composition for forming pixels, which can correspond to the demand of optical characteristics such as high pixel color concentration, high minuteness and high contrast required for color filters, and can simultaneously improve characteristics such as the coating characteristics and storage stability of pixel forming ink, to provide a method for forming a color filter, and to provide a color filter. <P>SOLUTION: The colored composition for forming the pixels, comprising a pigment and a dispersant, is characterized in that the pigment has a pigment having an average particle diameter of 10 to 150 nm, and the dispersant is a copolymer having polycyclic groups on side chains and is soluble in a pigment-dispersing medium. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a coloring composition for pixel formation (including base color, ink for pixel formation, paint, coating liquid, and coloring agents thereof), a color filter, and a method for producing the same, and more particularly has an affinity for a pigment. A coloring composition for forming a color filter pixel having excellent low-viscosity and long-term storage stability, a pixel excellent in color characteristics and optical characteristics, using a lyophilic copolymer having a polycyclic group in the side chain as a dispersant. The present invention relates to a color filter having performance and a method for producing the same.

  With the recent development of information devices, LCD color displays are used as information display members for televisions, projectors, personal computers, mobile information devices, monitors, car navigation systems, mobile phones, display screens for electronic calculators and electronic dictionaries, and information. It is used in a wide variety of information display related devices such as bulletin boards, information bulletin boards, displays of function display boards, sign boards, etc., and shooting screens of digital cameras and video cameras. Accordingly, color filters mounted on liquid crystal color displays have been required to have superior quality in terms of color characteristics and optical characteristics as image performance such as fineness, color density, light transmittance, and contrast.

  In pigment inks (coating liquids, etc.) used to form the three primary color pixels of conventional color filters, an anionic property such as a sulfone group is added to the molecular structure of pigments, commonly referred to as “synergists”, as pigment dispersion stabilizers. A combination of a pigment derivative (anionic pigment derivative) into which a group is introduced and an organic solvent-soluble dispersion aid (cationic pigment dispersion aid) having a cationic amino group as its counter ion, or a tertiary amino group Addition of a cationic pigment derivative having a cationic group such as an anionic polymer pigment dispersion aid in combination to improve the dispersion stability of the pigment in the organic solvent, lower the viscosity of the pigment ink, and stabilize for long-term storage I have maintained sex.

  However, color filters used for liquid crystal color televisions and the like are required to improve color display performance, for example, color density, light transmittance, contrast ratio, and the like. In order to improve the performance of the pixel, the particle diameter of the pigment tends to be further reduced. As a result, the pigment having the same mass is finely divided. As a result, the number of particles increases and the specific surface area of the entire pigment becomes very large. Therefore, in order to stably disperse the ultrafine pigment, the amounts of the pigment derivative and the pigment dispersion aid must be increased accordingly. However, due to the demand for higher color density of pixels, the demand for pixel coating composition such as higher pigment content has become stricter, making it very difficult to maintain the properties of the pigment ink.

  Therefore, the object of the present invention is to meet the demands for optical characteristics such as high density, high definition and high contrast of the pixel color required as a color filter equipped in a liquid crystal color television or the like. The object is to provide a coloring composition for forming a pixel, a method for producing a color filter, and a color filter, which improve characteristics such as application characteristics and storage stability of pixel forming ink (hereinafter sometimes simply referred to as “ink”). .

  As a result of diligent research to solve such problems, the present inventors have used a combination of the above-described ionic pigment derivative and counterion dispersing agent as a coloring composition for forming a color filter pixel. Without using, as a dispersant, an amphiphilic copolymer having a group having an affinity for the pigment in the side chain, the high content of the pigment is maintained, and the dispersant also functions as a film-forming component. Therefore, it is possible to prepare a color composition for forming a pixel of a color filter that maintains the contrast between the pigment and the film-forming component, has a low viscosity and has excellent long-term storage stability, and improves the color density of the pixel. In addition, the present inventors have found that color filter pixels having excellent optical characteristics such as transmittance and contrast ratio can be formed.

The above object is achieved by the present invention described below. That is, the present invention contains a pigment and a dispersant, the pigment is a pigment having an average particle size of 10 to 150 nm, the dispersant has a polycyclic group in a side chain, and the polycyclic group A pixel comprising 6.2 to 19.3% by mass of a monomer unit having a soluble unit in an organic solvent or a water-hydrophilic organic solvent mixed solvent which is a pigment dispersion medium A coloring composition for forming (the “coloring composition for forming a pixel” includes a base color for forming a pixel, an ink, a paint, a coating liquid, and a coloring agent thereof).

The polycyclic group is selected diphenylmethane, diphenylethane, diphenylpropane, diphenyl ether, diphenyl ether, diphenyl sulfone, styryl benzene, biphenyl, styryl biphenyl, naphthalene, fluorene, anthracene, acenaphthene, coumarin, residues groups quinoline and carbazole at least 1 Tanedea to be Ru.

The dispersant is a copolymer containing a lipophilic monomer unit having an aliphatic, alicyclic or aromatic hydrocarbon group, or a hydrophilic having an anionic, cationic and / or nonionic water-soluble group. a copolymer containing sex monomer units, for example, (a) the reaction product of a reactive compound having a polycyclic group in the molecule, soluble reactive copolymer dispersion medium, or (B) alpha having a polycyclic group, and beta-ethylenic addition-polymerizable monomer, alpha to form a polymer chain having an affinity to the dispersion medium, beta-ethylenic addition-polymerizable monomer and / Or it may be a copolymer with a macromonomer.

Examples of the pigment include quinacridone pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, perylene pigments, phthalocyanine blue pigments, phthalocyanine green pigments, isoindoline pigments, isoindolinone pigments, dioxazine pigments, and quinophthalone. Group consisting of pigment, nickel azo pigment, insoluble azo pigment, soluble azo pigment, high molecular weight azo pigment, carbon black pigment, composite oxide black pigment, iron oxide black pigment, titanium oxide black pigment, azomethine azo black pigment red selected from, green, blue, yellow, orange, purple, red, and a cyan or black pigment.

The composition, the polymer as further film-forming materials, oligomers and / or base containing monomers color, ink, paint, by coating liquid or the registry (hereinafter these may be referred to as "ink"), the pixel Used to form. The present invention further provides a method for producing a color filter characterized by using the above ink, and a color filter obtained by the method.

  According to the present invention, by using the dispersant as a dispersant for ink for forming a pixel of a color filter, it has a high pigment content, a high film-forming component, low viscosity, excellent long-term storage stability, and coating properties. Ink that does not decrease is provided, and by using the ink, a color filter having improved optical characteristics such as high color density, high definition, and high contrast of the pixel can be obtained, and the pixel equipped with the color filter The display device is excellent in pixel characteristics such as high color density, high definition, and high contrast.

  Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention. First, the dispersant used in the present invention and mainly characterizing the present invention will be described in detail. The dispersant mainly characterizing the present invention is a copolymer having a polycyclic group as a side chain in the molecule and soluble in a pigment dispersion medium.

  In order to stably disperse the pigment, which is a colored substance insoluble in the medium, into the dispersion medium in the form of ultrafine particles, an excellent dispersant is required. The properties required as a dispersant have an affinity for the pigment which is a dispersoid, adheres to the surface of the pigment even in the dispersion medium, does not leave, and dissolves in the dispersion medium in the liquid. Properties that contradict stable properties are required. In the present invention, both of these functions are solved by incorporating monomer units or polymer segments having the respective properties into the dispersant.

  Since organic pigments generally have a chemical structure with a chromophore linked to an aromatic group or a heterocyclic group, the aromatic group or heterocyclic group of the dispersant has a chemical structural affinity for the pigment. It is considered that the dispersant easily adheres to, deposits or accumulates on the pigment surface. However, phenyl phenyl, tolyl groups, xylyl groups, xylyl groups, hexylphenyl groups, dodecylphenyl groups, and other alkylphenyl groups that have a small number of carbon atoms in the ring are mostly compatible with organic solvents used in inks. Even if it adheres to the pigment surface, it is easily dissolved in the solvent solvent and desorbed from the pigment.

  The dispersant of the present invention comprises a benzene ring group connected in a molecule at least two, an aromatic group and a heterocyclic group having 8 or more carbon atoms constituting the ring, and a colorless or The copolymer has a polycyclic group selected from the group consisting of colored groups in the side chain and is soluble in the dispersion medium.

  The polycyclic group includes a benzene ring connected two or more, an aromatic group having 8 or more carbon atoms constituting the ring, or a heterocyclic ring having 8 or more carbon atoms constituting the ring. It is the residue of a compound containing a group. For example, conventionally known derivatives derived from diphenylmethane, diphenylethane, diphenylpropane, diphenylether, diphenylmethylether, diphenylsulfone, styrylbenzene, biphenyl, styrylbiphenyl, naphthalene, fluorene, anthracene, anthraquinone, acenaphthene, coumarin, quinoline, carbazole, etc. It is a group. Colorless groups containing those polycyclic groups or colored groups containing chromophores can be mentioned. Examples of the colored group include conventionally known dyes, pigments, groups having similar structures, intermediate groups, precursor groups, and the like.

  The polycyclic group in the dispersant may be the direct bonding of the polycyclic group to an addition polymerizable monomer unit such as an ethylenyl group or a propylenyl group, or an ester group, an amide group, a urethane group, a urea group, They are bonded via a linking group such as an ether group, a sulfoamide group, a methylene group, an amino group, a quaternary ammonium group, an aminotriazine group, and an oxytriazine group.

  Further, the dispersant used in the present invention has a group having affinity (disperse group) for the dispersion medium, and the amphiphilic group has an affinity for the dispersion medium in the pigment dispersion. Having a stable pigment dispersion effect. In the case where the dispersion medium is hydrophobic, the amphiphilic group is composed of an oleophilic monomer unit having an aliphatic, alicyclic or aromatic hydrocarbon group, and the amphiphilic group in the case where the dispersion medium is aqueous. Consists of anionic, cationic and / or nonionic hydrophilic monomer units.

The following method is mentioned as a typical synthesis method of the dispersant used in the present invention.
(A) A reactive compound having a polycyclic group in the molecule (hereinafter referred to as “reactive polycyclic compound”) and a reactive copolymer soluble in the dispersion medium (hereinafter referred to as “reactive amphiphilic copolymer”). And (B) an α, β-ethylene-based addition polymerizable monomer (hereinafter referred to as “polymer”) in which a polycyclic group is bonded directly or via a linking group in the molecule. "Polycyclic group-bonded monomer") and an α, β-ethylene-based addition polymerizable monomer (hereinafter referred to as "Amphiphilic Monomer") that forms a philic polymer chain copolymerizable therewith. A copolymer is referred to as a “mer”.

  Examples of the polycyclic group-bonded monomer or a copolymer of the cyclic group-bonded monomer unit (both will be referred to as monomers hereinafter) include 4-vinyl biphenyl and vinyl naphthalene that are directly bonded. , N-vinylcarbazole and the like. Moreover, the monomer which has a polycyclic group via a coupling group is obtained by making a reactive polycyclic compound and a reactive monomer react according to a conventional method. Examples of reactive groups in reactive polycyclic compounds and reactive monomers include alcoholic hydroxyl groups, primary, secondary, and tertiary amino groups; carboxylic acid groups, acid anhydride groups, acid halide groups, and alkyl ester groups. Carboxylic acid derivative groups such as isocyanate groups, epoxy groups, methylol groups, methoxymethyl groups, halogenated methyl groups, sulfochloride groups, chloroaminotriazine groups, chlorooxytriazines and the like, and reactive polycyclic compounds Groups that react with each other during the reaction with the reactive monomer are selected.

  Examples of the reactive polycyclic compound include diphenylmethane carboxylic acid, biphenyl carboxylic acid, naphthalene carboxylic acid, naphthalene acetic acid, anthracene carboxylic acid, anthraquinone carboxylic acid, fluorene carboxylic acid, and phenanthrene carboxylic acid. Reactive derivatives such as acids, acenaphthene carboxylic acids, coumarone carboxylic acids, quinoline carboxylic acids and their acid chlorides, alkyl esters; polycyclic compounds having alcoholic hydroxyl groups, compounds having phenolic hydroxyl groups, such as cumylphenol , Naphthol, methyl 2-hydroxynaphthoate, methyl 3-hydroxyanthracene-2-carboxylate, methyl 2-hydroxydibenzofuran-3-carboxylate, 2-hydroxycarbazo Reaction product of 1 mol equivalent or more of epoxy compound such as ethylene oxide and propylene oxide with polycyclic compound having methyl-3-carboxylate or the above carboxyl group; as polycyclic compound having amino group, polycyclic compound Examples include amino compounds obtained by direct introduction of amino groups or nitration and reduction.

  In addition, as the reactive group of the monomer unit of the monomer or copolymer to be reacted with the reactive polycyclic compound, one that reacts with the reactive group of the polycyclic compound is selected to form a linking group. Examples thereof will be described in the same manner as described above, for example, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, and acid chlorides, alkyl esters, acid anhydrides thereof; vinyls having a hydroxyl group. Alcohol (vinyl acetate as a precursor), hydroxyalkyl (2 to 6 carbon atoms) (meth) acrylate, polyethylene glycol (meth) acrylate; glycidyl (meth) acrylate having an epoxy group, etc .; isocyanate ethyl (meth) having an isocyanate group Acrylate, isocyanate-α-methylstyrene, etc .; styrenesulfonyl chloride having a sulfonyl chloride group, etc .; chloromethylstyrene having a halogenated methyl group, a methylol group, an alkoxymethyl group, N-methylol (meth) acrylic Bromide, N- methoxy (meth) acrylamide and the like, coupling reaction is done by known methods by a combination of the respective reactive groups.

  Examples of the lipophilic monomer having affinity for the hydrophobic dispersion medium include monomers that give conventionally known hydrophobic polymers. For example, aliphatic (C1-C30) alcohol ester, alicyclic (C4-C30) alcohol ester, aromatic (C6-C30) of α, β-ethylenically unsaturated carboxylic acid such as acrylic acid, methacrylic acid, and crotonic acid. ) Alcohol esters, alkoxy (C1-C4) alkyl (C2-C4) esters, etc .; aliphatic (C1-C30) alcohols of unsaturated dibasic acids such as maleic acid, fumaric acid, itaconic acid, alicyclic (C4- C30) monoesters and diesters with alcohol, aromatic (C6-C30) alcohol, etc .; styrene derivatives such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene derivatives; vinyl acetate; butadiene, isoprene, ethylene, propylene, Examples include olefins such as butylene.

  Examples of the hydrophilic monomer having affinity for the hydrophilic dispersion medium include monomers that give conventionally known hydrophilic polymers. For example, monomers having an anionic group include, for example, α, β-ethylenically unsaturated carboxylic acids such as acrylic acid and methacrylic acid, unsaturated dibasic acids such as maleic acid and itaconic acid, and half alkyls thereof. (C1-C18) ester, styrene sulfonic acid, vinyl sulfonic acid, hydroxyalkyl (C2-C4) (meth) acrylate sulfate ester, etc .; As the monomer having a nonionic group, the above α, β-ethylene Ethylene glycol esters, polyethylene glycol esters, alkoxy polyethylene glycol esters, glyceryl (meth) acrylates, etc. of cationic unsaturated carboxylic acids; monomers having a cationic group include dimethylaminoethyl (meth) acrylate, 3- (trimethylammonium ) -2-Hydro Sea methacrylate hydrochloride, include hydrophilic monomers such as vinyl pyridine. In addition to the low molecular weight monomer, a macromonomer composed of an addition polymer or condensation polymer having an addition polymerizable group is also used.

  In synthesizing the dispersant used for the hydrophobic dispersion medium, it is preferable to copolymerize an ionic monomer, a nonionic monomer, or a reactive monomer with the hydrophobic monomer. When the polymer of the film-forming material has an anionic group or a cationic group in the hydrophobic pigment dispersion system, a monomer having a cationic group or an anionic group of the counter ion is shared. It is preferable because it can be polymerized to form a counterionic dispersant, and the film-forming polymer and the dispersant can be ionically bonded to each other to bring about medium affinity and improve stability. Copolymerization of the reactive monomer is preferable because it provides a cross-linking bond as a film-forming material and can be strengthened. In the synthesis of the hydrophilic dispersant, copolymerization of the hydrophilic monomer with a hydrophobic monomer or a reactive monomer is not only a pigment dispersant but also a film forming material. This is also preferable.

  As a dispersion medium when using the hydrophobic dispersant, known (C1-C6) alcohols, alkylene (C2-C6) glycols, poly (C2-C6) alkylene glycols, polyhydric alcohols, those Examples thereof include organic solvents such as alkyl (C1 to C4) monoether, -diether, -monoether monoacetate, esters, ketones, aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. As a dispersion medium when using a hydrophilic dispersant, water or water and (C1-C3) alcohols, alkylene (C2-C3) glycols, polyalkylene (C2-C3) glycols, which are known aqueous media, Examples thereof include mixed media with polyhydric alcohols, water-soluble solvents such as alkyl (C1 to C3) monoethers, -diethers, and -monoether monoacetates.

  Alkali can be used to solubilize the ionic hydrophilic dispersant in an aqueous medium. The alkali to be used is not particularly limited, and examples thereof include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, ammonia, primary, secondary, and tertiary organic amines. Sodium oxide, potassium hydroxide, ammonia, (mono-, di-, tri-) ethanolamine and the like are preferable.

The compositions of the present invention, in addition to the pigment and the dispersant, the organic solvent agent or water as a dispersion medium - hydrophilic organic solvent mixed solvent is used. Moreover, when using the composition of the said invention as ink, a film forming material is contained further. In addition to being prepared directly, the ink is prepared as an ink using the composition of the present invention. The average particle size of the pigment contained in the ink is 10 to 150 nm, the dispersant is a copolymer of a polycyclic group-bonded monomer and a philic monomer, and is also known as a film forming material The following polymers, oligomers and / or monomers are used.

  The pigments used in the present invention are all known organic pigments, and specifically include quinacridone pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, perylene pigments, phthalocyanine pigments, halogenated phthalocyanine pigments. Pigment, isoindoline pigment, isoindolinone pigment, indigo / thioindigo pigment, dioxazine pigment, quinophthalone pigment, nickel azo pigment, insoluble azo pigment, soluble azo pigment, high molecular weight azo pigment, carbon black pigment, composite oxidation Red, green, blue and yellow, orange, purple or black pigments selected from the group consisting of organic pigments and inorganic pigments such as organic black pigments, iron oxide black pigments, titanium oxide black pigments, azomethine azo black pigments Is mentioned.

  As a particularly preferable pigment, when a red pixel pattern is formed, examples of the red pigment include a color index (CI) pigment red (PR) 56, 58, 122, 166, 168, 176, 177, 178, 224, 242, 254, and the like. Examples of the green pigment include pigment green (PG) 7, 36, poly (14-16) bromocopper phthalocyanine, poly (12-15) bromo-poly (4-1). Examples include chlorocopper phthalocyanine, and examples of the blue pigment include pigment blue (PB) 15: 1, 15: 3, 15: 6, 60, and 80.

  As a complementary pigment or a multi-color pixel pigment for the above pigment, as a yellow pigment, for example, Pigment Yellow (PY) 12, 13, 14, 17, 24, 55, 60, 74, 83, 90, 93 126, 128, 138, 139, 150, 154, 155, 180, 185, 216, 219, and the like, and pigment violet (PV) 19, 23, and the like can be used. Examples of black pigments for the black matrix include pigment black (PBK) 6, 7, 11, 26, copper / manganese / iron-based composite oxides, and the like.

  Although the usage-amount of the pigment of the composition of this invention is not specifically limited, Usually, it is used in the ratio of 5-500 mass parts per 100 mass parts of resin components which form a colored film. In addition, the composition of the present invention is used to prepare a pixel forming ink. The composition in which the pigment is stably finely dispersed in a high concentration in advance is preferably 5 to 40% by mass, preferably 10 to 10% by mass. The dispersant is preferably contained in an amount of 30% by mass, and the dispersant is preferably used in an amount of 5 to 300 parts by mass, more preferably 10 to 100 parts by mass, per 100 parts by mass of the pigment.

  At this time, in order to impart ionicity to the pigment and improve the dispersion stability of the pigment, the anionic or cationic pigment derivative and the cation or anionic polymer as a counter ion are stabilized. An agent may be added.

  The film-forming material for fixing the pigment in the present invention is not particularly limited, and any polymer, oligomer, and monomer, which are known film-forming materials conventionally used for color filter inks, can be used in any combination. . Further, a solvent or an aqueous medium as a dispersion medium suitable for the film forming material is used. Moreover, conventionally well-known additives, for example, a dispersion aid, a smoothing agent, an adhesive agent, and the like are appropriately added and used as necessary.

  As the film forming material, a photosensitive resin varnish and a non-photosensitive resin varnish are used. Examples of the photosensitive resin varnish include photosensitive varnishes used for ultraviolet curable inks and electron beam curable inks. Non-photosensitive resin varnishes include, for example, letterpress ink, planographic ink, intaglio gravure ink, and stencil. Resin varnishes used for printing inks such as screen inks, binders used for inkjet printing, resin vehicles used for electrodeposition coating, binders used for developers of electronic printing and electrostatic printing, binders used for thermal transfer films or ribbons Etc.

  Specific examples of the photosensitive resin varnish include, for example, photosensitive cyclized rubber resins, photosensitive phenol resins, photosensitive polyacrylate resins, photosensitive polyamide resins, photosensitive polyimide resins, and unsaturated polyesters. Resins, polyester acrylate resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, polyol acrylate resins, etc., or varnishes to which low molecular weight monomers are further added as reactive diluents Is mentioned. A preferred resin in the photosensitive resin varnish is an alkali developable polyacrylic acid ester copolymer having a free carboxylic acid group in the molecule.

  Specific examples of the non-photosensitive resin varnish include, for example, a cellulose acetate resin, a nitrocellulose resin, a styrene (co) polymer, a polyvinyl butyral resin, an aminoalkyd resin, a polyester resin, and an amino resin modified polyester. Water-soluble resin, polyurethane resin, acrylic polyol urethane resin, soluble polyamide resin, soluble polyimide resin, soluble polyamideimide resin, soluble polyesterimide resin, hydroxyethyl cellulose, styrene-maleic acid ester copolymer Salts, water-soluble salts of (meth) acrylic acid ester-based (co) polymers, water-soluble amino alkyd resins, water-soluble amino polyester resins, water-soluble polyamide resins, and the like. These may be used alone or in combination of two or more. Used in combination It is.

  In producing a color filter using the ink of the present invention, when a photosensitive resin varnish is used as a film forming material, a conventionally known photopolymerization initiator such as benzoin ether or benzophenone is added to the ink. It is used as a photosensitive ink prepared by kneading by a known method. Moreover, it can replace with said photoinitiator and can also use it as a thermopolymerizable ink using a thermal polymerization initiator.

  When a color filter pattern is formed on a substrate using the above ink, the above ink is coated on a transparent substrate using, for example, a spin coater, a low-speed rotation coater, a slit coater, a roll coater, a knife coater, etc. Or performing full printing by various printing methods or partial printing slightly larger than the pattern, and after pre-drying, the photomask is brought into close contact, and exposure is performed using an ultrahigh pressure mercury lamp to print the pattern. Subsequently, development and washing are performed, and post-baking is performed as necessary to form a color filter pattern. These color filter pattern formation methods are known per se, and the color filter pattern formation method is not particularly limited in the present invention.

  When forming a color filter pattern using a non-photosensitive ink using a non-photosensitive resin varnish, the ink is applied to a transparent substrate such as a glass substrate or a plastic substrate by the various printing methods described above. A method of printing a pixel pattern directly on a substrate, a method of forming a pixel pattern on a substrate by electrodeposition coating as an aqueous electrodeposition coating composition for a color filter, and coloring a substrate by inkjet printing as an ink for ink jet Color filter substrate after patterning method, electronic printing method or electrostatic printing method, or once colored pattern is formed on transparent film base material or transferable film base material for pasting by the above method etc. For example, a method of pasting or transferring to a film.

  Then, according to a conventional method, baking is performed as necessary, polishing for smoothing the surface, or top coating for protecting the surface is performed. Further, an RGB color filter can be obtained by forming a black matrix according to a conventional method. The manufacturing methods of these color filters are known per se, and the manufacturing method of the color filters is not particularly limited in the present invention.

  Next, the present invention will be described in more detail with specific examples. In addition, unless otherwise indicated, the part and% in a sentence are mass references | standards. Further, the molecular weight is a weight average molecular weight unless otherwise specified.

<Synthesis Example 1>
A polymerization reactor equipped with a water bath, a stirrer, a monomer dropping device, a reagent inlet, a backflow cooler, and a nitrogen gas inlet was prepared as a heating device. In a polymerization vessel, 150 parts of propylene glycol monomethyl ether acetate (PGMA) was charged as a polymerization solvent. Separately, methacrylic acid ester of naphthyl (-β-) oxy-polyethylene glycol (polycyclic group-bonding monomer-1, NPEGMA) 16.1 parts, benzyl methacrylate (BzMA) 23.9 parts, cyclohexyl methacrylate (CHMA) ) 20.0 parts, diethylaminoethyl methacrylate (DEAEMA) 10 parts, methacrylic acid (MAc) 30.0 parts and azobisisobutyronitrile (AIBN) 5 parts as a polymerization initiator, and a monomer containing a polymerization initiator A solution was prepared. One third of the mixture was added to a polymerization vessel containing PGMA, and the remaining two-thirds were added dropwise, and a polymerization reaction was performed at 70 to 80 ° C. for 8 hours under a nitrogen gas stream. A PGMA solution of an NPEGMA-BzMA-CHMA-DEAEMA-MAc copolymer having a PEG chain as a spacer and a naphthyl group in the side chain was obtained (solid content 40%). Hereinafter, the copolymer is referred to as “dispersant-1”.

  The methacrylic acid ester of naphthyloxy-polyethylene glycol used above was obtained by adding naphthyl (-β-) oxy-polyethylene glycol (average degree of polymerization of ethylene oxide: 4.5) obtained by adding ethylene oxide to β-naphthol. The acid chloride was synthesized by esterification according to a conventional method. The approximate molecular weight is 410.

<Synthesis Example 2>
In the same manner as in the polymerization reaction of Synthesis Example 1, 150 parts of PGMA as a polymerization solvent and methacrylic acid ester of naphthyl (-β-) oxy-polypropylene glycol (polycyclic group-bonded monomer-2, NPPGMA) 19.3 as a monomer Part, BzMA 20.7 parts, butyl methacrylate (BMA) 20.0 parts, DEAEMA 10 parts and MAc 30.0 parts are polymerized and NPPGMA-BzMA-BMA-DEAEMA-MAc having a PPG chain as a spacer and a naphthyl group in the side chain A PGMA solution of the copolymer was obtained (solid content 40%). Hereinafter, the copolymer is referred to as “dispersant-2”.

  The methacrylic acid ester of naphthyloxy-polypropylene glycol used above was obtained by adding naphthyl (-β-) oxy-polypropylene glycol (average degree of polymerization of propylene oxide: 6) obtained by adding propylene oxide to β-naphthol. The acid chloride was esterified and synthesized. Its approximate molecular weight is 491.

<Synthesis Example 3>
Similar to the polymerization reaction of Synthesis Example 1, 150 parts of PGMA as a polymerization solvent, 6.6 parts of β-hydroxynaphthoic acid (m-methacryloylamino) anilide (polycyclic group-bonded monomer-3, NASMA) as a monomer, BzMA33 .4 parts, CHMA 20.0 parts, DEAEMA 10 parts and MAc 30.0 parts were polymerized, and a NASMA-BzMA-CHMA-DEAEMA-MAc copolymer having β-hydroxynaphthoic acid anilide (naphthol AS) residues in the side chain A PGMA solution was obtained (solid content 40%). Hereinafter, the copolymer is referred to as “dispersant-3”.

  The β-hydroxynaphthoic acid (m-methacryloylamino) anilide was synthesized by esterifying methacrylic acid chloride with β-hydroxynaphthoic acid (m-amino) anilide. The molecular weight is 346.

<Synthesis Example 4>
NASA-BzMA-CHMA-DEAEMA having 4.1 parts of 2-chloro-5-trifluoromethylaniline diazotized and having the β-hydroxynaphthoic acid anilide (naphthol AS) residue obtained in Synthesis Example 3 in the side chain A red copolymer having a 2′-chloro-5′-trifluoromethylphenyl-azo-β-hydroxynaphthoic acid anilide in the side chain was obtained by a coupling reaction with a solution containing 100 parts of the -MAc copolymer. . Hereinafter, the obtained red copolymer is referred to as “dispersant-4”. This Dispersant-4 is suitable as a dispersant for the red pigment PR242.

  Since NASMA used in Synthesis Example 3 and the obtained copolymer, NASMA-BzMA-CHMA-DEEMA-MAc copolymer have a β-hydroxynaphthoic acid anilide residue, various known diazo components as described above And azo dye residue by coupling reaction. Red and orange copolymers (dispersants) are used as dispersants for red pigments such as PR177, 242, 254. The blue copolymer is used as a dispersant for a blue pigment such as PB15: 6, and the purple copolymer is used as a dispersant for a purple pigment such as PV23.

<Synthesis Example 5>
In the same manner as in the polymerization reaction of Synthesis Example 1, 150 parts of PGMA as a polymerization solvent, 35.0 parts of BzMA as a monomer, 10 parts of styrene (St), 10.0 parts of hydroxyethyl methacrylate (HEMA), 10.0 parts of DEAEMA, and MAc 30.0 The polymerization reaction was carried out using a part. Subsequently, a PGMA solution containing 5.58 parts of 1,3-bis (anthraquinonyl-1-amino) 5-chloro-s-triazine was dropped, and the mixture was subjected to a condensation reaction at 125 ° C. for 7 hours to obtain a yellow copolymer solution. Got. A PGMA solution of a BzMA-St-HEMA-DEAEMA-MAc copolymer having a bis (anthraquinonyl-1-amino) -s-triazine (BAT) group in the side chain was obtained (solid content 20%). Hereinafter, the yellow copolymer is referred to as “dispersant-5”.

  The 1,3-bis (anthraquinonyl-1-amino) 5-chloro-s-triazine used above is double moles of 1-amino to cyanuric chloride (1,3,5-trichloro-s-triazine). -Synthesized by reacting anthraquinone.

  Since the BAT group is a residue of a yellow pigment, Dispersant-5 is suitable as a dispersant for yellow pigments such as PY138, 139, and 150. Furthermore, yellow pigments can be used as dispersants such as PR 177, 242, 254 for red pigments and PG 7, 36 for green pigments, etc., which are used for complementary colors.

<Synthesis example of polymer dispersion aid>
Separately, as a pigment dispersion aid, as in the polymerization reaction of Synthesis Example 1, 150 parts of PGMA as a polymerization solvent, 15 parts of methyl methacrylate (MMA), 15 parts of ethyl methacrylate (EMA), 20 parts of CHMA, 20 parts of butyl acrylate ( BA) 20 parts, HEMA 15 parts and MAc 15 parts were used to carry out the polymerization reaction. As a polymer type dispersion aid, a 40% PGMA solution of MMA-EMA-CHMA-BA-HEMA-MAc copolymer was prepared. Hereinafter, the copolymer is referred to as “polymer dispersion aid”.

[Example 1]
(A) Refinement treatment of used pigments PR254, PG36, PY139, PY150, PB15: 6, and PV23 were prepared as pigments to be used as color filter pigments, and sequentially refined by the following method. 100 parts of each pigment was charged into a kneader equipped with a pressure lid together with 400 parts of sodium chloride and 130 parts of diethylene glycol. Premixing was performed until a uniformly moist mass was formed in the kneader, and then the pressure lid was closed and the contents were pressed and kneaded for 7 hours while being pressed at a pressure of 6 kg / cm ² . After 3,000 parts of the obtained ground product was put into 2% sulfuric acid and stirred for 1 hour, it was filtered to remove sodium chloride and diethylene glycol, washed thoroughly with water, dried and pulverized. A powder pigment was obtained. The average particle size of each ground pigment was about 30-50 nm.

(B) Preparation of high-concentration pigment dispersion (base color) for pixel formation Using the materials described in the first column of Table 1 below, blending the respective parts, stirring the mixture with a dissolver for 2 hours, After confirming that the lump was removed, the dispersion treatment of the pigment was performed using a horizontal medium disperser. As the pigment, the respective finer pigments obtained in the above (a) were used.

  When the average particle diameter of the pigment of the obtained pigment dispersion liquid of each color was measured, the average particle diameter was about 30 to 50 nm, and the refined pigment was sufficiently finely dispersed. Further, the viscosity of the pigment dispersion was 10 to 20 mPa · s as an initial viscosity, and was kept at 40 ° C. for 5 days as a storage stability test, and the viscosity was measured. The viscosity change was small and a value of 10 to 20 mPa · s was shown, indicating sufficient stability.

(C) Preparation of ink The materials described in the first column of Table 2 below were used, the respective number of parts described were blended, and sufficiently mixed with a mixer to obtain inks (color resists) of the respective colors.

  In the above, the photosensitive acrylic resin varnish is an epoxy acrylate resin, TMPTA is trimethylolpropane triacrylate, HEMPA is 2-hydroxyethyl-2-methylpropionic acid, and DEAP is 2,2-diethoxyacetophenone. Show.

(D) Preparation of red, green and blue glass substrates A glass substrate treated with a silane coupling agent was set on a spin coater, and the red ink-1 prepared in (c) above was first spin-coated at 300 rpm for 5 seconds. did. Next, pre-baking was performed at 80 ° C. for 10 minutes, and exposure was performed with a light amount of 100 mJ / cm ² using an ultrahigh pressure mercury lamp to obtain a red glass substrate. In the same manner as the above spin coating operation, set the glass substrate treated with the silane coupling agent on a spin coater, apply the above green and blue inks, perform exposure and curing, and obtain green and blue glass substrates. It was. The resulting color glass substrate has excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance, and excellent optical characteristics such as light transmission and contrast ratio. It was shown to be excellent as an ink for color filters.

[Example 2]
The glass substrate treated with the silane coupling agent was set on a spin coater, and the red ink-1 prepared in Example 1 (c) was first spin-coated at 300 rpm for 5 seconds and then at 1,200 rpm for 5 seconds. . Next, prebaking was performed at 80 ° C. for 10 minutes, a photomask having mosaic pixels was brought into close contact, and exposure was performed with an ultrahigh pressure mercury lamp at a light amount of 100 mJ / cm ² . Next, development and washing were performed with a dedicated developer and a dedicated rinse to form red mosaic pixels on the glass substrate.

  Subsequently, using the green ink-1 and the blue ink-1 prepared in the same (c), coating and baking are performed in the same manner as above to form green pixels and blue pixels, and a color filter having RGB pixels Got. The obtained color filter has excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance, and excellent light transmission properties, and is excellent as a color filter for liquid crystal color displays. Showed the properties.

  Moreover, it replaced with the dispersing agent-1 used in Example 1, and prepared the pigment dispersion liquid and ink of each color like Example 1 using the dispersing agent-2 obtained by the synthesis example 2, and each color of each color was prepared. A glass substrate was obtained, and physical properties and optical properties were evaluated. In the same manner as in Example 1, a color filter having RGB pixels was obtained. This also showed excellent properties as a color filter for liquid crystal color displays.

[Examples 3 to 5]
In place of Dispersant-1 used in Example 1, pigment dispersions and inks of respective colors were prepared in the same manner as in Example 1 using Dispersants-3-5 obtained in Synthesis Examples 3-5. Glass substrates of each color were obtained, and physical properties and optical properties were evaluated. In the same manner as in Example 1, a color filter having RGB pixels was obtained. These also showed excellent properties as color filters for liquid crystal color displays.

  According to the present invention, the use of a lyophilic copolymer having a polycyclic group having an affinity for the pigment in the side chain as a dispersant requires conventionally, and the addition amount does not increase as the pigment becomes finer. It is possible to disperse the pigment without using the ionic derivative of the pigment and the counterionic polymer dispersing aid, which are not obtained, or by reducing the addition amount. Accordingly, the amount of pigment can be increased accordingly, and the used dispersant also functions as a film-forming component. The base color or ink for pixel formation has low viscosity and excellent long-term storage stability, and the ink has excellent coating properties. By using it for pixel formation, the color density, high definition and high contrast of the pixel are increased. A color filter with improved optical characteristics can be obtained. The pixel display device equipped with the color filter manufactured as described above also has excellent performance in pixel characteristics such as high color density, high definition, and high contrast.

Claims (7)

Containing pigments and dispersants,
The pigment is a pigment having an average particle size of 10 to 150 nm,
The dispersant is selected from the group consisting of residues of diphenylmethane, diphenylethane, diphenylpropane, diphenylether, diphenylmethylether, diphenylsulfone, styrylbenzene, biphenyl, styrylbiphenyl, naphthalene, fluorene, anthracene, acenaphthene, coumarin, quinoline and carbazole. An organic solvent or a water-hydrophilic property which has at least one polycyclic group in the side chain, contains 6.2 to 19.3 mass% of the monomer unit having the polycyclic group, and is a pigment dispersion medium A colored composition for pixel formation, which is a copolymer soluble in an organic solvent mixed solvent .   The dispersant is a copolymer containing a lipophilic monomer unit having an aliphatic, alicyclic or aromatic hydrocarbon group, or a hydrophilic unit having an anionic, cationic and / or nonionic water-soluble group. The composition according to claim 1, which is a copolymer containing a monomer unit.   The dispersant is (A) a reaction product of the reactive compound having the polycyclic group in the molecule and a reactive copolymer soluble in the dispersion medium, or (B) α having the polycyclic group. , Β-ethylene-based addition polymerizable monomer and a copolymer of α, β-ethylene-based addition polymerizable monomer and / or macromonomer forming a polymer chain having affinity for the dispersion medium The composition of claim 1.   The pigment is a quinacridone pigment, anthraquinone pigment, diketopyrrolopyrrole pigment, perylene pigment, phthalocyanine blue pigment, phthalocyanine green pigment, isoindoline pigment, isoindolinone pigment, dioxazine pigment, quinophthalone pigment, Selected from the group consisting of nickel azo pigments, insoluble azo pigments, soluble azo pigments, high molecular weight azo pigments, carbon black pigments, composite oxide black pigments, iron oxide black pigments, titanium oxide black pigments, azomethine azo black pigments The composition according to claim 1, which is a red, green, blue, yellow, orange, purple, crimson, indigo or black pigment.   The composition as a base color, ink, paint, coating solution or resist according to claim 1, further comprising a polymer, oligomer and / or monomer as a film-forming material.   A method for producing a color filter, comprising using the composition according to claim 5.   A color filter formed by the method according to claim 6.